<?php

class Log{
  private $LogFile;
  private $logLevel;
  const DEBUG = 100;
  const INFO  = 75;
  const NOTICE = 50;
  const WARNING =25;
  const ERROR  = 10;
  const CRITICAL = 5;
  private function __construct($cfg=[]){
    $cfg = array(
        'LOG_FILE'=>'log.txt', 
        'LOG_LEVEL'=>75 //INFO
    );  
    $this->logLevel = isset($cfg['LOG_LEVEL']) ? $cfg['LOG_LEVEL']:LOG::INFO;
    if(!isset($cfg['LOG_FILE']) && strlen($cfg['LOG_FILE'])){
      throw new Exception('can\'t set file to empty');
    }
    $this->LogFile = @fopen($cfg['LOG_FILE'],'a+');
    if(!is_resource($this->LogFile)){
      throw new Exception('invalid file Stream');
    }
  }
  public static function getInstance(){
    static $obj;
    if(!isset($obj)){
      $obj = new Log();
    }
    return $obj;
  }
  public function LogMessage($msg, $logLevel = Log::INFO,$module = null){
    if($logLevel > $this->logLevel){
      return ;
    }
    date_default_timezone_set('Asia/shanghai');
    $time = strftime('%x %X',time());
    $msg = str_replace("\t",'',$msg);
    $msg = str_replace("\n",'',$msg);
    $strLogLevel = $this->levelToString($logLevel);
    if(isset($module)){
      $module = str_replace(array("\n","\t"),array("",""),$module);
    }
    $logLine = "$time\t$msg\t$strLogLevel\t$module\r\n";
    fwrite($this->LogFile,$logLine);
  }
  public function levelToString($logLevel){
     $ret = '[unknow]';
     switch ($logLevel){
        case LOG::DEBUG:
           $ret = 'LOG::DEBUG';
           break;
        case LOG::INFO:
           $ret = 'LOG::INFO';
           break;
        case LOG::NOTICE:
           $ret = 'LOG::NOTICE';
           break;
        case LOG::WARNING:
           $ret = 'LOG::WARNING';
           break;
        case LOG::ERROR:
           $ret = 'LOG::ERROR';
           break;
        case LOG::CRITICAL:
           $ret = 'LOG::CRITICAL';
           break;
     }
     return $ret;
  }
}

/*
$logIns = LOG::getInstance([]);
print_r($logIns);
$logIns->logMessage("test",LOG::INFO,'myTest');
*/
